Lighting fixtures adapted for operation in outdoor environments are commonly used to illuminate optical fibers. These systems mounted above ground, employ exterior shields to protect the internal components from rain and water splashed from adjacent pools or ponds. The optical fibers may be positioned in decorative arrays around a pool or pond, and also illuminate the pool. Often, a color wheel is interposed between the light source and the inlet ends of the optical fibers to enhance the visual effects with colored light from the fibers. Cooling air is drawn into the housing, circulated around the inlet ends of the optical fibers and the light source, and then channeled from the fixture under a pressure differential established by a fan positioned along the cooling path of air flowing through the fixture.
Various attempts have been made to configure these lighting fixtures with a low profile above the ground, and to prevent the internal light source from leaking (spurious) light from the light box to the adjacent area. However, such above-ground fixtures are vulnerable to collision with people and moving equipment such as carts and bicycles, and to associated damage from such collisions. They are also vulnerable to intrusion by wildlife such as insects or rodents that may disturb sensitive components, or to dirt and dust that accumulates over time on the optics to reduce their light output.
Another approach is to channel the spurious light into a translucent globe and so make the light box visible. See, for example, U.S. Pat. No. 5,779,353, entitled "Weather-Protected Lighting Apparatus and Method." This approach, however, draws attention to the light source and away from the dramatic and aesthetically pleasing fiberoptic pool-lighting display.
It would be desirable to provide a lighting fixture with fiber connections that could be buried beneath the surface of the ground. This would require the lighting fixture to be completely sealed. This, in turn, would require the lighting fixture to be efficient enough to deliver ample illumination at a sufficiently low power to avoid the need for external cooling air.